During the design or characterization of a vehicle HVAC system it may be necessary or desirable to measure the flow of cooling fluid or coolant through a particular component of the HVAC system. For example, it may be necessary to measure the flow of coolant through the radiator, the engine and/or the heater core(s) of the vehicle. In order to obtain an accurate coolant flow measurement, the pressure at the inlet of the HVAC system (e.g., at the point where the outlet of the flow meter attaches to the HVAC system) and the pressure at the outlet of the HVAC system (e.g., at the point where the inlet of the flow meter attaches to the HVAC system) must be balanced such that both the inlet pressure and the outlet pressure are the same. A variety of factors may effect the inlet pressure and outlet pressure of the HVAC system including air trapped in the HVAC system and debris and/or corrosion products flowing through the HVAC system. Air trapped in the HVAC system is particularly problematic when balancing the inlet and outlet pressures of the HVAC system.
Current devices for measuring coolant flow do not provide a mechanism by which air may be easily and reliably purged from the HVAC system and/or the coolant flow measurement device. Further, the current systems and devices currently used to measure coolant flow do not provide for balancing the pressure between the inlet and the outlet of the HVAC system. Accordingly, the coolant flow measurements obtained with such systems and devices may not provide accurate, repeatable measurements on a consistent basis.
Accordingly, a need exists for alternative devices and methods for measuring the coolant flow through a vehicle HVAC system.